Method of forming staybolt connections



Jan. 19, 1937.

I INVENTOR: WEI man J Fishers,

BY W

TTORNEYS.

Patented Jan. 19, 1937 UNITED STATES PATENT OFFICE-V METHOD OF FORIVHNG STAYBOLT CONNECTIONS Herman J. Peters, Columbus, Ohio Application June 10, 1935, Serial No. 25,861

1 Claim. (Cl. 29-15711) This invention relates to methods of forming tive boiler. The side sheet is represented at I, staybolt connections, and, though applicable and the first step of the process consists in drillgenerally to the art of joining a staybolt to a ing holes 2 corresponding in number and locarelatively thin metal sheet, it is particularly usetion to the staybolts 3 to be used, such holes be- 5 ful as a method of connecting the staybolts of a ing made of a diameter considerably smaller 5 locomotive boiler to the side sheets thereof. than the outside diameter of the heads 9 of the One object of the method of the present instaybolts to be inserted therein. vention is to increase the area of contact be- When the side sheet I has been thus perfotween the head of the staybolt and the sheet to a d, i iS p a d in a power Dress having a 1 which it is applied, and thus to establish a more plun r 4 and tt m i 5 as p s n ed in steam-tight and firm connection b tw n th se Figs. I and II. In accordance with the preferred elements. Another object of the invention, in P ct e, t e p u e 4 is fo med with a conical its application to a locomotive boiler, is to protapered Shank 5 and a hemispherical heed vide a minimum exposure of the parts of such the Size of the plunger Corresponding 3 to a joint to the fire side of the boiler sheet, and the Size of the d 9 0f t Staybelt 3. The 15 thus to increase the life of the joint. Still ancompl m n a y i 5 is f annular formation other object of the invention is to provide an With an inside diameter larger t an the diamannular flange surrounding the hole in the sheet e 0f the p er head 1.

in which the staybolt is inserted and serving to In F the parts a represented in the p reinforce and materially strengthen the sheet, t o s o up d p ato to fo c the p unger at the same time creating no interference with 4 through e e i the side sheet I. Downnecessary expansion and contraction. ward movement of the plunger 4 causes the The staybolt connection formed according to hemispherical head 7 to be forced through t this invention avoids many of the djfliculties hole 2 with incidental pressing out Of an annular formerly experienced with older methods of conflange 3 as Shown n The annular 25 necting staybolts to side sheets. It eliminates flange 8 defi a cavity tapering w s th end cracking of the sheet at the holes, and makes pos- 0f the fiange- After the flange 8 as t us been sible an increase in the number of threads at the ed, the i ner Wall thereof is threaded as inregion of contact between the staybolt and sheet. dieated a The Steyboit head po The connection formed according to the method ly threaded as indicated at H, is then in- 30 of my invention is further characterized by a serted in the cavity and screwed to tight fitting tapered cavity at the hole in the sheet adapted engagement. The final step of the process con for the application of a similarly formed head sists in riveting the head 9, as indicated at l2, of a staybolt, which provides a particularly firm to close fitting contact with the sheet I and withsteam-tight connection. in the confines of the mouth of the cavity, thus 35 Other objects and advantages characterizing presenting a minimum of exposed metal at that my present invention will become more fully apside of the sheet. parent from the description hereinafter set forth It will be particularly observed that the flange of one example of the method as applied to a 8 is so formed'that a substantially large bearing 40 locomotive boiler, having reference to the acarea is provided between the inner wall of the 40 companying drawing. Of the drawing: flange 8 and the head 9 of the staybolt. As shown Fig, I represents a portion of a boiler side in Fig. III, the staybolt head 9 is in contact with sheet, showing a die and plunger in association the flange 8 over a distance measured longituditherewith preparatory to the formation of an nally of the staybolt,.as represented at X, which annular flange at a hole in the sheet. is greater than the thickness of the side sheet. 45

Fig. II is a View similar to Fig. I, showing the Furthermore, it will be noted that the flange B position of the parts when the plunger'has is formed at the water side, rather than at the entered the die to complete the formation of the fire side, of the side sheet I, thus reducing to annular flang a d a minimum the exposure of the parts of the stay- Fig. III represents in cross section the assembolt connection to the extreme heat of the fire. 50 bled side sheet and staybolt when the joint/has With a joint of the character described, the been completed. presence of the flange around the hole in the In the drawing, there is represented an exsheet acts as a reinforcement which materially ample of the invention as applied to the art of strengthens the sheet, while at the same time joining staybolts to the side sheets of a locomocreating no interference with expansion and contraction. Accordingly, the difficulties formerly experienced with joints of this character, and caused by inadequate bearing surface between the sheet and staybolt, are eliminated. Particularly, the tendency of the side sheet to crack at the joint is avoided, and the formation of a conical cavity establishes a firm connection between the parts.

While I have described one example of my invention, as applied to boiler practice,- it willbe apparent that various changes may be made in the steps and instrumentalities employed in forming a joint of the character described, all without departing from the spirit of my invention as defined in the annexed claim.

Having thus described my invention, I claim:

The method of joining a staybolt having a preformed flaring head to a sheet which consists in drilling a preliminary circular hole in the sheet of smaller diameter than the staybolt to ease a subsequent punching operation, punching a rounded plunger through said hole, the size of said plunger corresponding closely to the size of said tapered head, thereby producing an annular flange on said sheet, said flange defining a substantially conical cavity narrowing towards the end of the flange, taperingly'threading said flange interiorly, inserting therein a staybolt having a correspondingly shaped and similiarly taperingly threaded head fitting the cavity aforesaid, and riveting the head in place.

HERMAN J. PETERS. 

